The cast resin foam insulation that is now common in refrigerator and freezer insulation has the advantage of being strong, adherent to most surfaces, easy to install and with a high insulation value so that the desired degree of insulation can be obtained with relatively small thicknesses of the foam.
These characteristics also, however, create problems in certain instances. Thus where there are extremes of contraction and expansion under changing thermal conditions the adherence can create high stress in certain areas such as those in which the relatively thin plastic liner has one or more projecting portions such as the above-mentioned shelf retainer means due to locking of the liner in recesses in the foam formed by such projections even when the liner surface facing the foam is provided with a laminate release layer as disclosed in copending Weiss et al. application Ser. No. 502,006, filed Aug. 30, 1974, (PA-4800) and assigned to the assignee of the present application. This close fit of the insulation foam resists movement between liner and foam during contraction and expansion due to differences in the coefficient of thermal expansion of the liner material and the insulating foam.
One of the features of this invention therefore is to provide an improved freezer cabinet in which changes in temperature with resulting excessive stress being placed on the liner in normal construction but with this invention cushioning areas that would normally be subject to high stresses with the result that the thermal changes that the freezer cabinet and particularly the plastic liner undergo will not damage the liner.